Gameplay Mechanics: Regenerating Health

Health packs!Every shooter in the history of the genre has had some form of health system. As you get hurt, your health decreases, and you die when it hits zero. This is very cut-and-dry throughout most games. Of course, there must be some way of recovering that health though. There are some variations, though it’s one area that I think some good mechanics can still be created for. Many games have had different ways of recovering health, but the form we’ve seen the most often is that it regenerates automatically with no action from the player. It’s become very popular in most shooters and other genres and I’ve seen it implemented in several mods for Doom, Quake and other games. However, many don’t seem to realize all the different effects this has on different aspects of gameplay. Now, there are a few misconceptions regarding what regenerating health actually does because it’s so often paired with a few other mechanics: namely cover mechanics, slow movement speed, dominantly hitscan attacks, checkpoints and reloading weapons. There are several games that feature some or even all of the mechanics at the same time, and each one brings their own set of considerations. Because they’re so often featured with regenerating health, it’s very easy to associate the effects of one with the other mechanics. In this article, I’ll write about health recovery systems specifically, and will try to avoid consequences that these other systems introduce.
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Player Upgrades: Other Considerations

Now that we’ve covered the two forms of progression, there are other elements that affect both in different ways. Additionally, the two aren’t mutually exclusive, and can interact in different ways. In this article, we explore these topics.

As evidenced by games like Doom and Singularity, both kinds of upgrade progression can benefit from hiding certain upgrades, money or tokens in secrets hidden around the map. Doom often hid weapons in secrets (chaingun hidden on the second map, rocket launcher on the third, etc.), along with other very helpful items. Singularity was one of those games that featured both a money and token system, and often hid BOTH across maps. I like this because it can draw the player further into the game, making him explore around and appreciate some of the graphical details he might not notice if he was just trying to get to the end. I think Dead Space could’ve benefited from this to draw the player further into the game (something important for survival-horror shooters like that), but all of the credits and power nodes were somewhat obvious.

Unfortunately, hiding upgrades or some form of upgrade currency in secrets can be hard to pull off correctly. Secret weapons can potentially wreck the progression curve in your game, to the point where there really doesn’t feel like it’s easing you into the progression at all. In Duke Nukem 3D, you can literally get every weapon available in the first episode in the first map. It’s balanced by the fact that ammo for some of them is limited so you can’t use the RPG or pipe bombs as often as you might want, but there’s still not much actual progression there. Quake 2, over the course of the much-longer game did introduce weapons more slowly, but still did have more advanced weapons hidden in secrets. The super shotgun was first available in a secret map in the first unit (essentially halfway through the unit); the next earliest is a secret at the very end of unit 1; the first time it’s obviously available is at the start of unit 2. The first rocket launcher is in a secret at the start of unit 4. The first time you can find the BFG is a secret in unit 6 (out of 8). It gets around that problem of ruining progression by spacing them out quite a bit more, so it still feels like a slow progression.

A potential problem with hiding currencies to upgrades in secrets is that it’s tricky to strike a balance with how much to hide, and how much to keep open. In several games that hide currency in money systems, especially (Singularity, Red Faction: Armageddon, etc.), very sharp players end up with a massive surplus of them, even if they’re used for other things, like Deus Ex: Human Revolution. One game that did this better was Hard Reset, where a certain amount of points gets you an upgrade. However, not many of those upgrades made you more powerful (beyond the obvious two or three that you’ll likely get first), so it didn’t mess with the game’s balance much. Tokens end up working better in this regard because they can be balanced more easily than amounts of credits. When you hide money, you’re hiding some abstract amount; it could be big part of a small upgrade, a small part of a big upgrade, etc.. When you hide tokens, that’s a whole upgrade (or half of a better upgrade, or whatever)! You can more easily plan for the player having this amount of upgrades (what’s in plain sight) while accounting for the player having all of the possible upgrades. This is one of the main strengths of the token system.

Another consideration is how open-world the game is. By open-world, I mean the game has defined objectives, but doesn’t care how they’re accomplished or whether you do them quickly, and even has optional side-missions. Crysis (the first half) and Red Faction: Guerrilla, for example, had gameplay like this. Because the game is open-ended by definition, a linear progression is difficult to pull off correctly. How can you know a player will be at this location to pick up this new weapon? Crysis (and Crysis: Warhead) occasionally had caches of weapons designated as secondary objectives, usually with a powerful new weapon as an introduction. Red Faction: Guerrilla had a combination between player-driven and linear progression; after completing certain missions, new weapons become available to unlock with salvage (money), and occasionally new enemy soldiers show up with new weapons (which you can pick up). Because you can’t introduce weapons in Quake 2’s style of linear progression, you have to tie weapons to particular events, or risk the player just missing the progression.

Player-driven upgrade systems can work better in open-world games, though, because the player might be able to go back and pick up upgrades that might be needed for some part of the game. For example, in missions in Red Faction: Guerrilla where you have to capture a vehicle but you don’t have an Arc Welder (makes vehicle capturing much easier because it kills the driver without damaging the vehicle), you could go looking for salvage to unlock it beforehand. It’s easier to balance around, since the developer can assume the player has some kind of upgrade, because the player could go somewhere else, get that upgrade, then return. This is one instance where I think allowing the player to grind for infinite upgrade currency can work, but I have never liked it for more linear games because it encourages the player to sit in one particular area, often in a style of game that encourages the player to keep moving forward.

One other factor with player-driven upgrades is to prevent the player from getting particular upgrades until he’s progressed to a certain point of the game. In Wolfenstein 2009, you can upgrade weapons and Veil powers with gold hidden in the game. Many more powerful upgrades aren’t more expensive than previous ones, but they require certain levels be completed before you can purchase them. Similarly, Red Faction: Armageddon has certain tiers of upgrades. The first tier is available from the start, but the higher tiers with more powerful upgrades are locked until you reach certain milestones in the single-player game. Another take on this is the schematic system in Dead Space and Singularity; You don’t even know about these upgrades until you find schematics hidden in the levels (in Dead Space, these take up inventory space, so you actually have to decide if you want it). In Dead Space, they were fairly obvious, but many of them were hidden in Singularity. This system adds a tone of linear progression to a player-driven progression system; preventing the player from getting too powerful, too early in the game, and slowly introducing him to new powers.

Something that might surprise you is how upgrade progression and story go together. One way in which Red Faction: Armageddon feels horribly unfinished is that some of its upgrade system isn’t explained in story at all. In the backstory for the game, it says the main character has been upgrading the Nanoforge bit by bit, so this is simply a continuation of that. What isn’t explained, however, is why certain tiers of upgrades are locked, why an upgrade to the Nanoforge lets his guns store more ammo, or things like that. While it doesn’t affect the gameplay, things like this can hurt the player’s immersion if there are widely unexplained and implausible elements like this, which can lessen enjoyment (if the player cares about that). It might not be very serious, but again, worth consideration.

As you can see, you don’t have to commit to either a player-driven or linear form of progression. In fact, I think the best method is a combination of both; mostly linear with some minor player-driven upgrade system. Red Faction: Armageddon, though I think it was rushed, did have both used quite well. As you progressed through the game, you found new, more powerful (or more useful) weapons. Additionally, you found salvage (currency) for purchasing upgrades for your Nanoforge (granting new usable abilities and upgrades for your character). You could customize your weapon loadout to fit your play style, and upgrade how you wanted to fit that; you could take melee weapons and explosives and upgrade your explosive and melee damage, for example. Or pick a longer-range loadout, increase your damage with headshots and the clip size of your weapons. It locks some more powerful upgrades until you’ve progressed a certain way into the game, as well, so you have to progress in power as the game steps up its difficulty, and you are prevented from beelining to the powerful upgrades you want. Additionally, the game also got harder because they actually assumed the player did get some upgrades (and it’s still possible to beat the game if you don’t even get any, though it is much harder), and indeed the game actuallygives the player several upgrades in the form of weapons, which the player uses more often than anything else.

This also isn’t limited to shooters; RPGs, strategy games and some other genres all feature progression. Think of Starcraft 2, where each new mission in the campaign introduced you to a new unit you can use (linear), and can upgrade certain things outside of missions (player-driven). Starcraft 2 also did a very good job working it into the story, as well, with explanations for how each upgrade works in the game’s lore, and the reasons why you’re getting these new units in the campaign. Level-based RPGs also blend the two very nicely, with Baldur’s Gate and Torchlight being perfect examples. Progressing through the game gets you experience and loot, experience gets you levels, which increase your power. Just about everything I’ve talked about about in this article works with these types of games as well.

Upgrading the player is almost essential to these genres of games. Shooters can get dull if the player never increases in capability in some way, and RPGs are entirely built around it. In order to implement a proper system for it, you have to understand all the different ways a player can acquire those upgrades. I don’t believe for a second that this is everything that affects how he gets upgraded (it was all I could think of), but hopefully these articles are a good place to start in how you design your system.

Player Upgrades: Player-Driven Progression

The second kind of progression, player-driven progression is where the player picks and chooses what upgrades to get. It’s usually accomplished through a purchase system of some sort, though some first-person shooters with role-playing elements use this for their RPG mechanics (Deus Ex: Human Revolution is a great example of a game with a shooter’s balance and gameplay with RPG mechanics, as opposed to Fallout 3 which is a first-person RPG with guns).

The best example of this is the original Dead Space, where every single weapon (except the first weapon, the Plasma Cutter) and upgrade has to be bought. Weapons and new suits (armor and inventory upgrades) are purchased with credits you find scattered in maps or dropped from enemies, while upgrades to those weapons and to yourself (air meter, health or other categories) are accomplished through power nodes you find or can buy with a large amount of credits. The player does find schematics throughout the game for new things that can be unlocked, but that’s not as much linear progression because it’s up to the player to actually unlock those himself.

There are two methods of currency I’ve seen in recent games for purchasing upgrades in this manner. The first is where it takes a certain amount of some common resource (which I’ll refer to as a money system) and the second is where it takes just one of some much-rarer resource (a token system). Dead Space uses both; it uses credits as a money system (used to buy new weapons and suits), and power nodes as a token system (used to upgrade those weapons and yourself). Often times if a game has both, it’ll let you use your money to purchase a token, as Dead Space does by letting you buy power nodes with a large amount of credits (Deus Ex: Human Revolution and Singularity are good examples as well). There are some benefits to both.

Money systems allow players to get a more steady stream to inch more steadily to an upgrade, so they feel like there is constant progress towards it. It can let the player gauge how long it will take to get a particular upgrade. If you hide money around maps to reward players for exploring (like is often the case), you can also add a surplus to reward inquisitive players. Now, the big problem with that is that you can often have a big surplus towards the end of the game. In Deus Ex: Human Revolution (even without the DLC that gives you 10,000 credits), you can still get enough credits to buy the ammo you might need as you need it, weapons and weapon upgrades you want, and all the praxis points you can buy, and still have a surplus at the end of the game. Also, when I talk about money systems, I mean specifically referring to upgrades; not buying ammo, health items or things like that. However, in these games where you can use currency for items like that, you can often have a large surplus of those items anyway.

Some games tie the money system in with killing monsters. In both Binary Domain and Crysis 2, for example, that was the only method you have of getting that currency. You might have to be careful with this, though, if you have potentially-infinite monsters because that could allow the player to just farm money. In the case of Crysis 2, there were limited monsters and only a few varieties gave you that currency. Binary Domain only has infinitely spawning monsters in one or two spots, but you definitely do not want to stick around there because you can run out of ammo or other resources. There are some arguments about this, but I don’t think it’s a good thing to let the player farm money for upgrades in shooters, specifically. In older RPGs farming money for armor or weapons was part of the gameplay and no problem at all, but I feel like it’s a problem in shooters because it can screw up the game balance. If the player can spend some amount of time when a group of upgrades become available getting all of those upgrades, then he can screw up the balance. There are arguments that if the player wants to dedicate the time to that then he should be allowed to, but player-rights-versus-developer-design is another article. I will speak about a game that gets around this problem in the last article of this series.

Make sure there aren’t problems with how you give the player this money, if they get it from killing monsters. Binary Domain just adds it to your counter, but Crysis 2 has some problems. Monsters just drop it when they die and you have to walk to their corpses to collect, but it’s actually just a separate pickup that’s very hard to spot, and if you don’t pick it up within a certain time period then it vanishes. In a game that rewards you for playing carefully, you don’t want your rewards vanishing. It would have gone better if the bodies themselves gave the currency (would’ve fit the story better, as well), and had some more obvious indicator that the currency was available from that body. Dead Space, I think, got it right; monsters can drop credits when they die, but you have to pick it up, the pickup is pretty obvious, and they never vanish.

Token systems, however, feel a lot simpler; you find an item, you can buy an upgrade. However, it’s a trickier balance between how important each token should be in terms how strong the upgrade is, or how rare the tokens are to get. While this is a subjective opinion-piece, one other pitfall I think token systems can fall into is when a single token won’t buy you the upgrade. Dead Space had an upgrade tree with its power nodes where you could only move onto more upgrades by fitting power nodes into adjacent slots to that upgrade.

Unfortunately, this meant most of the power nodes you were using… weren’t being spent on upgrades, they were spent on “empty” slots to get closer to slots that actually contained upgrades. With token systems, you want to give the player more of a payoff every time, because he’s usually working so hard to find or acquire these tokens (though they were more common in Dead Space, but you still probably weren’t going to be able to max out a whole weapon and your suit). Singularity had this to a much lesser degree with Weapon Tech upgrades. Each weapon had three categories (usually reload speed, damage and clip capacity) that could be upgraded twice. The first upgrade takes one Weapon Tech, and the second upgrade takes two. Deus Ex: Human Revolution did the same thing, with some augmentations taking two praxis points to unlock. That’s not nearly as bad, however, because the player is still getting that payoff because it requires that many to get the upgrade before it takes both, rather than having to put one in specifically for nothing. It’s like the game telling you “Okay, you just spent that point and got nothing for it!” rather than “Okay, this upgrade is good enough to take a bit more than the usual cost to upgrade.” It also blurs the difference between money and token systems, which should be distinct from one another because they have their own strengths and weaknesses; when they combine, they get most of the weaknesses, but the strengths don’t usually combine as well.

Another major difference between money and token systems is that the upgrades have to be balanced differently depending on which you use. With a money system, you can make an upgrade more powerful or more useful than others, and then balance it by making it cost more than other upgrades. For example, Singularity had several very useful upgrades (more maximum health) that cost more than others, and some that are downright useless (more breath underwater) but didn’t cost much. With token systems (with every upgrade costing one or maybe two tokens), the upgrades have to be balanced around that, so they’re roughly equivalent. This works better with games that allow multiple play styles, like Deus Ex: Human Revolution, as all of the upgrades (with a rare exception) are equally useful, just in different ways.

There’s one major downside I’ve found to this method; it’s much, much harder to balance your game if you exclusively use this method. Several people say Dead Space gets too easy as the game goes on, and this is because the developers can’t assume the player has any specific upgrades. The developers have an idea that the player could have the level 5 suit at the end of the game, but he very well might not have bought it, or might not have even picked up the schematic. Though slightly harder, every enemy can be killed with the Plasma Cutter because the developers made sure you can, as they just don’t know what weapons you bought and what you haven’t when they place those monsters in the map. Granted, while the game is pretty hard if you don’t get any upgrades, if the developer assumes the player has a certain level of strength, he risks the game being unfinishable because the player might not have what’s necessary to progress. Again, at the end of this series when I bring all of this together, I will give an example of one game that gets around this problem perfectly.

The good thing about this system is that it gives the player the freedom to upgrade what he wants to upgrade. If he’s good with a particular weapon or if there’s something keeping him from using it well, he can upgrade it. If there’s a weapon he doesn’t like the look of, he can skip it. It can potentially let the user have the game cater to his play style, rather than forcing a particular play style from him. Deus Ex: Human Revolution is famous for having so many upgrades catering to different play styles so you could run through the game as an ordinary shooter, as passive stealth, or as an assassin. Some of those upgrades were outright useless, but the majority allowed you to play in different ways.

An increasing amount of shooters over the last decade have been using player-driven progression more and more. If you’re implementing this kind of progression in your game, it should be carefully thought out and balanced. I hope this breakdown helps readers to understand this system a bit better.

Player Upgrades: Linear Progression

In every single-player shooter and most adventure games, there is some progression in player strength. Most commonly, the player gains access to new weapons, or more health, or similar upgrades. In designing a game, how you introduce these upgrades is very important. I’ll work on breaking it down as much as possible and covering every element I can think of while giving my opinion of what works and what doesn’t, but because this article turned out much, much longer than I originally thought it would, I’m going to cover this in a few parts. Bear in mind, I won’t talk about role-playing games (either first-person or otherwise) such as Fallout 3, the Elder Scrolls series, or more conventional RPGs; mostly just shooters with upgrade mechanics.

There are two kinds of upgrade pacing, but by far the most common type is a linear progression, meaning as you go through the game, upgrades (most commonly weapons) are slowly introduced to you. The earliest shooters, from Wolfenstein 3D to Quake 2, did this with just weapons, but other games do introduce more than that kind of upgrade. Probably the best example of this would have to be Warhammer 40,000: Space Marine. It didn’t just give you new weapons; it powered up just about every aspect of your character, and all at specific points of the game. Additionally, it gave you introductions as to what each upgrade was and the capabilities of each new weapon, so you knew what you were getting and had ample opportunity to test it.

Easily the best feature of linear progression is that it’s a lot easier to balance the game around. In Space Marine, the developers know exactly what upgrades and weapons the player will have at any particular point in the game. This is especially valuable if your game has an increasing progression of monsters, as well, where new, more powerful varieties of monsters appear as you move through the game. Some games like Halo and Crysis try to take this further by limiting you to a certain amount of weapons you can carry at a time, so you wouldn’t have this one weapon that could make this encounter too easy. Using a limited-weapon mechanic for balance like this is not something I agree with, but that’s something for another article.

The major problem with a strict linear progress (As in Space Marine) is that it reduces the replay value, because it’s always going to be the same progression each time you play. Games like Doom and Duke Nukem 3D, however, weren’t particularly linear; they had some more advanced weapons stored in secrets early on, so you could jump ahead of the curve. For example, in the first episode of Doom, there was a rocket launcher hidden in a secret in the third map. Otherwise, you might not get one until the seventh (though ammo was limited before, and even after that). With a more lenient progression, it can add replay value because the player might be able to jump ahead of the curve. This does come with its own benefits and problems, but I will talk about hiding items of progression in secrets in the third part of this series.

Speaking of Doom, in the earliest shooters from Wolfenstein 3D up to Quake, if you died on a level, you restarted that level with just your default weapon (usually referred to as pistol-starting, because the default was usually the pistol). This meant that the developer had to consider another dimension in the progression; whether the player came from a previous map, or whether he just started this one. In the more contemporary style of games it’s not an issue, but if that is a mechanic you want then this is something to consider. Usually this goes with a more arcadey style of map design, like those aforementioned games.

Another variation on the standard linear progression are games like Red Faction: Guerrilla, where new weapons become available at certain parts of the game, but aren’t simply handed to you. The player might possibly miss a weapon depending on how the game is laid out (I never found the Rail Driver in Red Faction: Guerrilla, for example), but I think that more open-world games (Crysis 1, Red Faction: Guerrilla, System Shock 2) work well with this more than other variations of linear progression.

While most of what I talk about is specifically with regard to single-player, several multiplayer shooters these days use a form of linear progression with an experience system to make players more powerful. Most Call of Duty titles (which have become the model for this kind of multiplayer progression) and even Space Marine did this, where they give new perks and weapons that are just plainly more powerful than the earlier ones. I really hate this idea, because it gives some players flat out more damage because they have been playing longer. There’s really no worse idea for a game than to punish a potentially decent portion of your audience just for not being part of the first group to play it. Space Marine tries to get around this by letting you copy the equipment loadout of the previous player who killed you, but when you have mechanics like that, then why do you even have the progression if you can do that anyway? It also starts feeling like hard work to get a weapon you want, and when a player plays a game, he doesn’t necessarily want to feel like he’s doing work; he wants to have fun!

This is the most basic version of upgrading the player. He gets a certain way through the game, he gets something new and useful, he fights more powerful things with it. I think it goes very well if your game has an increasing difficulty curve and a matching progression of monsters. Quake 4, for example, keeps introducing new monsters along with new weapons far into the game. Usually I like when a game introduces a weapon or some other upgrade that counters (even partially counters) a new monster after introducing the new monster and showing how great a counter for it would be. While it is the most basic method of upgrading the player, I think linear progression can work the best. It’s simpler to implement and often makes the player feel like he’s progressing through a game.